Toshiba Tec Kabushiki Kaisha

Kabushiki Kaisha Toshiba

Hiroki Umezawa

Nobuhiko Nakahara

Noriyuki Kikuchi

Atsushi Kubota

Takayuki Sawada

Hidehiro Watanabe

William C Kress

Norimasa Ariga

Ronald Pellar

A print calibration processing apparatus includes a test image output section configured to outputs plural patches for gradation characteristic generation to an image forming section, a gradation characteristic data generation section configured to use, as a read object, a test chart obtained by printing the test images on both the sides of the print sheet by the image forming section while shifting print positions of the test images in a front and back direction, reads the images on a first and second side of the test chart, and generates gradation characteristic data of front test images on the first side and the second side and gradation characteristic data of show-through test images on the first and second side, a correction data generation section configured to determine a correction value of maximum gradation based on gradation characteristics of the front and the show-through test images, and a correction section configured to correct gradation of image data.

Print calibration processing apparatus, image forming apparatus, print calibration processing method and image forming method

According to one embodiment, a printing calibration processing apparatus includes: a gradation-characteristic-data generating section configured to read images of a printed surface and a rear surface of a test chart output by an image forming section and generate gradation characteristic data of the surfaces; a gradation-correction-date creating section configured to determine a correction value of maximum gradation on the basis of gradation characteristics of the surfaces; a color-material-amount-conversion-data creating section configured to determine a maximum of a color material on the basis of the correction value of the maximum gradation; a color-material-amount-limitation processing section configured to perform, concerning image data for printing, limitation processing for setting the maximum of the color material as an upper limit of a color material use amount; and a gradation correcting section configured to apply gradation correction to the image data subjected to the limitation processing using the gradation correction data.

Printing calibration processing apparatus, image forming apparatus, and printing calibration processing method

A method and apparatus of adjusting color conversion parameters to be used by a color printer for printing documents or images, includes receiving a user input designating a color conversion parameter to be adjusted. It also includes obtaining information as to at least one other color conversion parameter that is related to the user designated color conversion parameter. It further includes adjusting the user designated color conversion parameter based on a user selection of source color-to-destination color change, and adjusting the at least one other color conversion parameter related to the user designated color conversion parameter based on the same user selection of source color-to-destination color change.

Image processing apparatus and method

In accordance with the present invention, a system and method are described for producing pure gray tones on a multi-color document output device that includes a system for operating on device independent color data having multiple color components, which color data corresponds to one or more associated electronic documents. The system and method function to extract gray data by the use of tristimulus values in a range specified by a functional relationship of a selected tristimulus value.

System and method for extracting grayscale data in accordance with a prescribed tolerance function

It is an object of the invention to provide a technique for preventing image quality deterioration of a print image involved in adjustment of color conversion parameters in image formation processing. An image processing apparatus includes: a change information acquiring unit that acquires, when first brightness setting information is changed, information on the change, the first brightness setting information defining, in printing a color that can be represented by color materials of plural colors, brightness that should be represented using the color materials; a calculating unit that calculates, on the basis of the change information acquired by the change information acquiring unit, information on second brightness setting information defining, in printing a color represented only by a black color material, brightness that should be represented using the color material, the second brightness setting information making it possible to print an image of substantially the same brightness as an image printed using the first brightness setting information after the change; and a setting information changing unit that changes, on the basis of the information calculated by the calculating unit, setting content of the second brightness setting information.

Image processing apparatus, image processing method and image processing program

Contents of a text processing job is not pre-traced, and at a stage of processing a drawing object, a CLUT combination relating thereto is determined to be ON/OFF. A plurality of drawing objects are associated with a set of CLUT combination, and a CLUT combination which has been once ON is maintained as is ON.

Method and apparatus for color transformation (conversion)

A halftone processing section halftone-processes input image data using a plurality of dither threshold planes. An image output section having different output position accuracies between a main scan direction and a sub-scan direction outputs an image corresponding to halftone-processed image data. Each of the dither threshold planes consists of a plurality of the same unit threshold matrixes. In the unit threshold matrix, a relatively medium to high threshold array in a predetermined threshold range corresponding to the entire tone range of the input image data is an aperiodic array and an anisotropic array with neighboring thresholds having close values, in a direction coincident with a scan direction, in which the output position accuracy of the image output means is low. With this configuration, the image output section outputs an image having serial medium and high tone dots in the scan direction.

Image processor and color image processor

Halftone processing section carries out a halftone processing using a dither threshold plane on which thresholds in a predetermined threshold range corresponding to the tone range of input image data are arranged, and provides halftone-processed image data. Image output section has intrinsic, basic tone characteristics and outputs an image corresponding to the halftone-processed image data provided from the halftone processing section. The dither threshold plane consists of a plurality of same unit threshold matrixes and each of the unit threshold matrix consists of a plurality of sub-matrixes. An array of relatively low thresholds in the predetermined threshold range is equal among the plural sub-matrixes, and relatively medium thresholds and high thresholds in the predetermined threshold range are arranged periodically to extend over series of sub-matrixes.

A process computes a combination of chromatic and achromatic color dots for reproducing an input color signal based on a result of colorimetric measurement for a CIELab value. The process finds the sum of chromatic and achromatic color dot diameters. The process extracts combinations of chromatic and achromatic color dots wherein the sum of chromatic and achromatic color dot diameters is greater than or equal to a specified value. From the extracted combinations of chromatic and achromatic color dots, the process further extracts chromatic and achromatic color signals for recording a combination of chromatic and achromatic color dots containing the minimum achromatic color dot diameter and determines these signals as a color signal.

Color image generation apparatus and color image generation method

Image data of 256 gradations is converted into that of 4 gradations which can be recorded by a recording head, at a pseudo-halftone processing unit and the converted image data is supplied to a head driving unit. A control signal selector selects a control signal A from a control signal A setting unit when the image data is a natural image, and a control signal B from a control signal B setting unit when the image data is a character or a line drawing. The head driving unit generates an electric signal used to drive the recording head on the basis of gradation information from the pseudo-halftone processing unit and the control signal A or B. With this operation, when the image data is a natural image, recording is carried out with a pixel dot for image formation excellent in gradation property, and when the image data is a character or a line drawing, recording is carried out with a pixel dot for image formation which causes no jaggy or blur to be generated at hatched portions and the like.

Image forming apparatus

In a multilevel error diffusion process, an input image signal Din with tones and an image correction signal Ecd are added together to produce a corrected image signal Dinc, which in turn is converted into an eight-level image signal to provide an output image signal Dout with eight tones. To convert the input image signal into the output image signal, there are provided a plurality of conversion tables and a switching means for selectively switching the conversion tables at random. The conversion tables are switched with each pixel in the corrected image signal.

Image processing method and device and image formation device

Provided is an image formation apparatus for printing pixel dots on a recording paper at pitches smaller than intervals between ink jet-out ports by using an ink jet recording head while moving the recording head in a rotation shaft direction and feeding a recording paper around the drum so as to wind the drum. The ink jet recording head has a plurality of ink jet-out ports arranged in line and is movable in a rotation shaft direction of the drum. In the case where the image formation is completed by two rounds of the drum, the recording head is shifted at the time the first drum rotation is completed, by a moving step amount determined so as to correspond to a specific feature of a human visual system, thereby suppressing image formation that is non-uniform in concentration.

Growing community of inventors

Shizuoka-ken, Japan

Hiroki Umezawa